The electrical properties of zinc implanted GaAs

The electrical properties of zinc implanted GaAs have been measured as a function of ion dose, ion energy, implant temperature and annealing temperature and time using either evaporated aluminium layers or pyrolytically deposited Si₃N₄ as the encapsulant during annealing. The electrical profiles depend on all the above variables and thus profiles can be tailored by varying the relative magnitudes of these parameters. It is important to note that hole concentrations in excess of 1 × 10¹⁹ cm^?3 can be obtained following an anneal at temperatures as low as 650°C. Also, at the same annealing temperature, profile depths can be varied from 0.2 to about 1 μm by correct choice of implantation parameters. Aluminium coatings are acceptable for annealing temperatures up to 700°C but Si₃N₄ is required at higher temperatures.